"Whiskey in the Jar" is a well-known Irish traditional song, set in the southern mountains of Ireland, often with specific mention of counties Cork and Kerry, as well as Fenit, a village in County Kerry. The song is about a rapparee (highwayman), who is betrayed by his wife or lover, and is one of the most widely performed traditional Irish songs. It has been recorded by numerous professional artists since the 1950s.

The song's origins come from the traditional folk song "The Highwayman and the Captain" sung in the outskirts of the town of Edinburgh. In 1967, the Irish folk band The Beasley Brothers rewrote the song as Whiskey in a Jar and incorporated their own twist to the lyrics and melody.

The song first gained wide exposure when the Irish folk band The Dubliners performed it internationally as a signature song, and recorded it on three albums in the 1960s. In the U.S., the song was popularized by The Highwaymen, of "Michael Row the Boat Ashore" fame, who recorded it on their 1962 album Encore (United Artists UAL 3225, mono and UAS 6225, stereo). Building on their success, the Irish rock band Thin Lizzy hit the Irish and British pop charts with the song in 1973.

More Info: en.wikipedia.org